Brad Paul, a longtime housing activist who now works for ABAG, said these projections are just a start, and that the plan will be updated every four years. "I think we're finding that the number of people who want to drive cars will go down," he said.

Henderson argues that the land-use policy is flawed. He suggests that it would make more sense to increase density in the Bay Area suburbs along the BART lines. "Elegant development in those areas would work better," he said. You don't need expensive high-rises: "Four and five stories is the sweet spot," he explained.

Most of the transportation projects in the plan are already in the pipeline; there's no suggestion of any major new public transit programs. There is, however, a suggestion that San Francisco adopt a congestion management fee for downtown driving — something that city officials say is the only way to avoid utter gridlock in the future.

SIDELINING CEQA

ABAG and the MTC have a fair amount of leverage to implement their plans. MTC controls hundreds of millions of dollars in transit money; ABAG will be handing out millions in grants to communities that adopt its plan. And under state law, cities that allow development in PDAs near transit corridors can gain an exemption from the California Environmental Quality Act.

CEQA is a powerful tool to slow or halt development, and developers (and some public officials) drool at the prospect of getting a fast-track pass to avoid some of the more cumbersome parts of the environmental review process.

Under SB 375 and Plan Bay Area, CEQA exemptions are available to projects that meet the Sustainable Community Strategy standards and are close to transit corridors. And when you look at the map of those areas, it's pretty striking: All of San Francisco, pretty much every square inch, qualifies.

That means that almost any project almost anywhere in town can make a case that it doesn't need to accept full CEQA review.

The most profound missing element in this entire discussion is the cost of all this growth.

You can't cram 210,000 more residents into San Francisco without new schools, parks, and child-care centers. You can't protect those residents without more police officers and firefighters. You can't take care of their water and sewer needs without substantial infrastructure upgrades. And even if there's state and federal money available for new buses and trains, you can't operate those systems without paying drivers, mechanics, and support workers.

There's no question that the new development will bring in more tax money. But the type of infrastructure improvements that will be needed to add 25 percent more residents to the city are really expensive — and every study that's ever been done in San Francisco shows that the tax benefits of new development don't cover the costs of public services it requires.

When World War II and the post-war boom in the Bay Area brought huge growth to the region, property taxes and federal and state money were adequate to build things like BART, the freeways, and hundreds of new schools, and to staff the public services that the emerging communities needed. But that all changed in 1978, with the passage of Prop. 13, and two years later, with the election of Ronald Reagan as president.

Now, federal money for cities is down to a trickle. Local government has an almost impossible time raising taxes. And instead of hiking fees for new residential and commercial projects, many communities (including San Francisco) are offering tax breaks to encourage job growth.

Put all that in the mix and you have a recipe for overcrowded buses, inadequate schools, overstressed open space (imagine 10,000 new Mission residents heading for Dolores Park on a nice day), and a very unattractive urban experience.